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  • Küçük Resim Yok
    Öğe
    Effect of kisspeptin on calcium signalling in cultured rHypoE-8 cell line
    (Wiley-Blackwell, 2015) Kutlu, Selim; Ozdemir, Gokcen; Sahin, Zafer; Ozcan, Mete; Canpolat, Sinan; Kelestimur, Haluk
    [Abstract Not Availabe]
  • Küçük Resim Yok
    Öğe
    The effects of apelin on myometrium contractions in pregnant rats
    (C M B Assoc, 2018) Kacar, Emine; Ercan, Zubeyde; Serhatlioglu, Ihsan; Sumer, Aysegul; Kelestimur, Haluk; Kutlu, Selim
    Apelin, which is a new hormone, is secreted especially in the brain by hypothalamus as well as by many other organs like the stomach, fat tissue, and the heart. For apelin, whose possible effects on many bodily functions like the endocrine system, cardiovascular system and metabolic activities are still under investigation, the reproductive system is also an important target area. The purpose of the present study was to investigate the effects of plasma apelin levels in rats that were in diestrus, pregnancy and lactation periods, and to examine its possible effects on myometrium contractions of pregnant rats and non-pregnant rats that were in diestrus period. The plasma apelin concentrations in female adult Wistar rats were determined with the ELISA method in the diestrus period, and on the 12th, 18th, and 21st days of the pregnancy, and on the 2nd and 10th days of lactation (n=7 for each group). In addition, the effect of apelin at 0.01, 0.1, 1 and 10 mu M doses on isometric contractions in the rat uterus on the 21st day of pregnancy and in diestrus period was tested by using isolated organ bath. This protocol was repeated under conditions that were pre-treated with protein kinase C inhibitor in calcium-free medium, and the possible effect of apelin on contractions and the mechanisms that might mediate this effect were investigated. When plasma apelin levels were compared with the rats in diestrus period, the apelin concentrations in the 21-day pregnancy group were high at a significant level (p<0.05); and low at a significant level in the 2-day lactation group (p<0.05). In myometrium contraction trials, it was observed that apelin induced the contractions. Apelin increased the frequency of the myometrium contractions at a significant level when applied at 1 mu M and 10 mu M concentrations (p<0.05 and p<0.001). Only after the apelin application at 10 mu M concentration did the amplitude of the contractions increase at a significant level (p<0.01). In the myometrium of the rats that were on the 21st day of pregnancy, the frequency of the contractions was statistically significant at 0.1 mu M, 1 mu M and 10 mu M doses (p<0.01). In addition, the amplitude of the contractions increased at a statistically significant level at 1 mu M and 10 mu M dose application (p<0.05 and p<0.01, respectively). The apelin application induced the contractions in calcium-free medium. When apelin was applied after the pre-application with protein kinase C inhibitor, no contractions were observed. The present study showed that apelin levels were increased at the end of pregnancy in rats, and the hormone induced the uterus contractions. This effect does not occur with protein kinase C inhibitor and in calcium-free medium, which shows that protein kinase C pathway might play a role in these mechanism. These findings show that apelin might be an endogenous peptide that plays a role on uterine contractions at birth in rats.
  • Küçük Resim Yok
    Öğe
    The effects of apelin on myometrium contractions in pregnant rats
    (C M B Assoc, 2018) Kacar, Emine; Ercan, Zubeyde; Serhatlioglu, Ihsan; Sumer, Aysegul; Kelestimur, Haluk; Kutlu, Selim
    Apelin, which is a new hormone, is secreted especially in the brain by hypothalamus as well as by many other organs like the stomach, fat tissue, and the heart. For apelin, whose possible effects on many bodily functions like the endocrine system, cardiovascular system and metabolic activities are still under investigation, the reproductive system is also an important target area. The purpose of the present study was to investigate the effects of plasma apelin levels in rats that were in diestrus, pregnancy and lactation periods, and to examine its possible effects on myometrium contractions of pregnant rats and non-pregnant rats that were in diestrus period. The plasma apelin concentrations in female adult Wistar rats were determined with the ELISA method in the diestrus period, and on the 12th, 18th, and 21st days of the pregnancy, and on the 2nd and 10th days of lactation (n=7 for each group). In addition, the effect of apelin at 0.01, 0.1, 1 and 10 mu M doses on isometric contractions in the rat uterus on the 21st day of pregnancy and in diestrus period was tested by using isolated organ bath. This protocol was repeated under conditions that were pre-treated with protein kinase C inhibitor in calcium-free medium, and the possible effect of apelin on contractions and the mechanisms that might mediate this effect were investigated. When plasma apelin levels were compared with the rats in diestrus period, the apelin concentrations in the 21-day pregnancy group were high at a significant level (p<0.05); and low at a significant level in the 2-day lactation group (p<0.05). In myometrium contraction trials, it was observed that apelin induced the contractions. Apelin increased the frequency of the myometrium contractions at a significant level when applied at 1 mu M and 10 mu M concentrations (p<0.05 and p<0.001). Only after the apelin application at 10 mu M concentration did the amplitude of the contractions increase at a significant level (p<0.01). In the myometrium of the rats that were on the 21st day of pregnancy, the frequency of the contractions was statistically significant at 0.1 mu M, 1 mu M and 10 mu M doses (p<0.01). In addition, the amplitude of the contractions increased at a statistically significant level at 1 mu M and 10 mu M dose application (p<0.05 and p<0.01, respectively). The apelin application induced the contractions in calcium-free medium. When apelin was applied after the pre-application with protein kinase C inhibitor, no contractions were observed. The present study showed that apelin levels were increased at the end of pregnancy in rats, and the hormone induced the uterus contractions. This effect does not occur with protein kinase C inhibitor and in calcium-free medium, which shows that protein kinase C pathway might play a role in these mechanism. These findings show that apelin might be an endogenous peptide that plays a role on uterine contractions at birth in rats.
  • Küçük Resim Yok
    Öğe
    Nesfatin-1 may Interfere with Kisspeptin/kiss1 Systemin Gonadal Activity of Female Rats
    (Wiley, 2016) Sahin, Zafer; Cuce, Gkhan; Ozcan, Mete; Canpolat, Sinan; Gormus, Zulfikare Isik Solak; Kutlu, Selim; Kelestimur, Haluk
    [Abstract Not Availabe]
  • Küçük Resim Yok
    Öğe
    Oxytocin activates calcium signaling in rat sensory neurons through a protein kinase C-dependent mechanism
    (Springer, 2014) Ayar, Ahmet; Ozcan, Mete; Alcin, Ergul; Serhatlioglu, Ihsan; Ozcan, Sibel; Kutlu, Selim; Kelestimur, Haluk
    In addition to its well-known effects on parturition and lactation, oxytocin (OT) plays an important role in modulation of pain and nociceptive transmission. But, the mechanism of this effect is unclear. To address the possible role of OT on pain modulation at the peripheral level, the effects of OT on intracellular calcium levels ([Ca2+](i)) in rat dorsal root ganglion (DRG) neurons were investigated by using an in vitro calcium imaging system. DRG neurons were grown in primary culture following enzymatic and mechanical dissociation of ganglia from 1- or 2-day-old neonatal Wistar rats. Using the fura-2-based calcium imaging technique, the effects of OT on [Ca2+](i) and role of the protein kinase C (PKC)-mediated pathway in OT effect were assessed. OT caused a significant increase in basal levels of [Ca2+](i) after application at the doses of 30 nM (n=34, p<0.01), 100 nM (n=41, p<0.001) and 300 nM (n=46, p<0.001). The stimulatory effect of OT (300 nM) on [Ca2+](i) was persistent in Ca2+-free conditions (n=56, p<0.01). Chelerythrine chloride, a PKC inhibitor, significantly reduced the OT-induced increase in [Ca2+](i) (n=28, p<0.001). We demonstrated that OT activates intracellular calcium signaling in cultured rat primary sensory neurons in a dose-and PKC-dependent mechanism. The finding of the role of OT in peripheral pain modification may serve as a novel target for the development of new pharmacological strategies for the management of pain.
  • Küçük Resim Yok
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    Percentages of serum, liver and adipose tissue fatty acids and body weight are affected in female rats by long-term Central kisspeptin treatments
    (Taylor & Francis Ltd, 2023) Sahin, Zafer; Ozcan, Mete; Ozkaya, Ahmet; Canpolat, Sinan; Kutlu, Selim; Kelestimur, Haluk
    This study was conducted to determine the possible effects of long-term exogenous kisspeptin and its antagonist P234 on serum, liver and adipose tissue fatty acids (FA) profiles, as well as body weight, in female rats. Kisspeptin (50 pmol) and P234 (1 nmol) were administrated to the weaned Sprague-Dawley female rats by an intracerebroventricular injection from the 26th postnatal day to the 60th postnatal day. Percentages of the serum total saturated FA ( n-ary sumation SFA) and total monounsaturated FA ( n-ary sumation MUFA) were lower in the kisspeptin group. In the adipose tissue, n-ary sumation SFA was lower and total unsaturated FA higher in the P234 group. Moreover, long-term central kisspeptin injection caused a decrease in the body weight. When compared to the kisspeptin group, the final body weights were higher in the P234 and kisspeptin + P234 groups. According to our results, we suggest that kisspeptin has a regulatory role in FA metabolism and regulation of body weight.